Saving error return code in a pipeline

Saving error return code in a pipeline

[DervishD]

    Hi all :)

    Maybe I'm asking for something impossible, or maybe I'm just dumb
enough to not see the obvious solution...

    I have a script which returns an error code, but it outputs a lot
of info, so I call it like this:

    script.install |& tee install.log

    Obviously this 'masks' the return code, but I want to see the
output even though I'm saving it to a file, so a redirection doesn't
fit me well. I can use MULTIOS, of course, but I don't want to use it
for all my commands...

    Is there any better solution than this?:

    script.install >(tee install.log) 2>&1

    Thanks a lot in advance :))

    Raúl Núñez de Arenas Coronado

-- 
Linux Registered User 88736 | http://www.dervishd.net
http://www.pleyades.net & http://www.gotesdelluna.net
It's my PC and I'll cry if I want to...

Re: Saving error return code in a pipeline

[Dominic Mitchell]

On Thu, Jun 30, 2005 at 11:33:07AM +0200, DervishD wrote:
>     Hi all :)
> 
>     Maybe I'm asking for something impossible, or maybe I'm just dumb
> enough to not see the obvious solution...
> 
>     I have a script which returns an error code, but it outputs a lot
> of info, so I call it like this:
> 
>     script.install |& tee install.log
> 
>     Obviously this 'masks' the return code, but I want to see the
> output even though I'm saving it to a file, so a redirection doesn't
> fit me well. I can use MULTIOS, of course, but I don't want to use it
> for all my commands...
> 
>     Is there any better solution than this?:
> 
>     script.install >(tee install.log) 2>&1

Try looking at the pipestatus array.  It contains all the exit codes
from the last pipeline.  So you should be able to get the code you want
by examining $pipestatus[1].

-Dom

Re: Saving error return code in a pipeline

[Stephane Chazelas]

On Thu, Jun 30, 2005 at 11:33:07AM +0200, DervishD wrote:
>     Hi all :)
> 
>     Maybe I'm asking for something impossible, or maybe I'm just dumb
> enough to not see the obvious solution...
> 
>     I have a script which returns an error code, but it outputs a lot
> of info, so I call it like this:
> 
>     script.install |& tee install.log
> 
>     Obviously this 'masks' the return code, but I want to see the
> output even though I'm saving it to a file, so a redirection doesn't
> fit me well. I can use MULTIOS, of course, but I don't want to use it
> for all my commands...
> 
>     Is there any better solution than this?:
> 
>     script.install >(tee install.log) 2>&1
[...]

zsh has what it calls mult_ios (mult_ios option which is on by
default) that performs a tee internally when a fd is redirected
several times.

script.install >&1 > install.log 2>&1

Once zsh sees > install.log, it realises that it's the second
time fd 1 is being redirected, so it creates a pipe and a
background process that reads from that pipe and writes what
it's reading both to your terminal and install.log, then
redirects stdout to it. Then 2>&1 redirects stderr as well to
that pipe.


But you can also do:

script.install |& tee install.log
script_exit_status=$pipestatus[1]

-- 
Stephane

Re: Saving error return code in a pipeline

[DervishD]

    Hi Dominic :)

 * Dominic Mitchell <dom@happygiraffe.net> dixit:
> On Thu, Jun 30, 2005 at 11:33:07AM +0200, DervishD wrote:
> >     Is there any better solution than this?:
> >     script.install >(tee install.log) 2>&1
> Try looking at the pipestatus array.  It contains all the exit codes
> from the last pipeline.  So you should be able to get the code you want
> by examining $pipestatus[1].

    I completely forgot about pipestatus, and the worst part is that
I already use pipestatus in one of my scripts... Oh, my.

    Thanks a lot :)

    Raúl Núñez de Arenas Coronado

-- 
Linux Registered User 88736 | http://www.dervishd.net
http://www.pleyades.net & http://www.gotesdelluna.net
It's my PC and I'll cry if I want to...

Re: Saving error return code in a pipeline

[DervishD]

    Hi Stephane :)

 * Stephane Chazelas <Stephane@artesyncp.com> dixit:
> > I can use MULTIOS, of course, but I don't want to use it
> > for all my commands...
> > 
> >     Is there any better solution than this?:
> > 
> >     script.install >(tee install.log) 2>&1
> [...]
> zsh has what it calls mult_ios (mult_ios option which is on by
> default) that performs a tee internally when a fd is redirected
> several times.

    Look the paragraph above ;)

> But you can also do:
> script.install |& tee install.log
> script_exit_status=$pipestatus[1]

    Better solution for the script, thanks :)

    Raúl Núñez de Arenas Coronado

-- 
Linux Registered User 88736 | http://www.dervishd.net
http://www.pleyades.net & http://www.gotesdelluna.net
It's my PC and I'll cry if I want to...